A waiter is a male person who waits on tables in a restaurant, serving customer's food and drinks and clearing tables when they are finished.
A waiter is a female person who waits on tables in a restaurant, taking orders, serving customer's food and drinks and clearing tables when they are finished.
A wizard can also be known as a magician or a sorcerer. Wizards practise magic, and learn their art from many years of studying books. Wizards are usually portrayed as in the picture, as an old man with a long white beard, wearing robes and a pointed hat.
A writer is someone who writes books, stories or articles for a living. If you are writing a book it may take a very long time to find a company who will print it so that lots of people can read it. Most writers write for newspapers or magazines. Once someone has had something published, they are formally called a writer.